ML091890666

E-mail from R. Guzman to J. Dosa Acceptance Review Results of NMP2 Extended Power Uprate Application

ML091890666
Person / Time
Site:	Nine Mile Point
Issue date:	07/08/2009
From:	Richard Guzman Division of Operating Reactor Licensing
To:	Dosa J Nine Mile Point
Guzman R, NRR/DORL, 415-1030
References
TAC ME1476
Download: ML091890666 (2)

Text

From:

Guzman, Richard Sent:

Wednesday, July 08, 2009 11:33 AM To:

'Dosa, John J' Cc:

'Vandeputte, Dennis E'

Subject:

Nine Mile Point Unit 2 EPU Application - Acceptance Review

John, The NRC staff has completed its acceptance review of the subject license amendment request dated May 27, 2009, and has determined that the steam dryer portion of the submittal is unacceptable for review with the opportunity to supplement per NRR Office Instruction, LIC-109. Below is a list of the non-acceptance issues to be discussed during our 7/9/09, 1:30pm conference call. The purpose of the call will be to ensure that the staff's information needs are understood, discuss the appropriate next steps for action, and establish a target date for the supplemental response to be submitted (not to exceed 15 calendar days from the call). A formal letter documenting the non-acceptance of the application will be issued, as appropriate, following the call. All other review areas were found acceptable for staff review per LIC-109.

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DRAFT--------------------------

The NRC staff noted that the steam dryer analysis utilized Low Power (25% LP) data subtracted from the Current Licensed Thermal Power (CLTP) data; considered additional damping effects from perforated plate hydrodynamic damping; utilized stress reduction factors from the submodeling approach; utilized Acoustic Circuit Model (ACM) Rev. 4, which was not benchmarked for LP noise subtraction; and applied the bias and uncertainty values that were smaller than those previously approved for other EPU applications.

1. Non-Acceptance Issue: Acoustic Circuit Model (ACM) Benchmarking The main steam Line (MSL) strain gage signals at CLTP are modified by filtering the low flow (LF) plant noise as described by Equation (8) of the CDI Report 08-24P, Rev. 1, Stress Analysis of Nine Mile Point 2 Steam Dryer. The ACM Code described in the CDI Report 04-09 uses these filtered signals and generates the pressure loading on the steam dryer. The staff finds that such filtering of the LF plant noise is non-conservative and, therefore, not acceptable because no filtering of the LF plant noise was performed during the benchmarking of the ACM Code.

The ACM Code is benchmarked using the Quad Cities 2 (QC2) data with no LF noise subtraction to establish the bias and uncertainties. As previously accepted by the staff, the ACM Rev. 4 is currently benchmarked based on the QC2 data with LF noise included. The staff finds the subtraction of LF noise across the entire frequency range, unacceptable, for steam dryer qualification.

2. Non-Acceptance Issue: Requirement of 2.0 for Minimum Alternating Stress Ratio for the Steam Dryer The minimum alternating stress ratio (SR-a) for the NMP2 steam dryer at the proposed EPU conditions does not meet the accepted value of 2 when LF noise is not filtered. As stated above, the bias errors and uncertainties associated with ACM Rev. 4 are not benchmarked for noise subtraction. In the CDI Report,08-24P, the minimum alternating stress ratio (SR-a) is shown as 2.02 at the projected EPU conditions, when LP noise is subtracted or filtered. The licensee has not provided the stress ratio with noise not subtracted or filtered. Since LF noise subtraction is not allowed as discussed in the first non-acceptance issue for the reason that ACM is not benchmarked for the noise subtracted case, the dryers minimum stress ratio (SR-a) may fall much below the target value of 2 for EPU. Therefore, the staff has determined that the stress ratio of the dryer may not be acceptable for EPU.

The current submittal by NMPNS for NMP2 is incomplete and does not include minimum alternating stress ratios at CLTP and EPU without filtering the NMP2 plant noise (i.e., LF signal. The licensee is

requested to provide the minimum alternating stress ratios at CLTP and EPU without filtering the NMP2 plant noise (i.e., LF signal) and demonstrate that the minimum alternating stress ratio at EPU conditions is not less than 2.0.

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DRAFT--------------------------

Rich Guzman Sr. Project Manager NRR/DORL US NRC 301-415-1030 Richard.Guzman@nrc.gov E-mail Properties Mail Envelope Properties ()

Subject:

Nine Mile Point Unit 2 EPU Application - Acceptance Review Sent Date: 07/08/2009 10:55:27 AM Received Date: 07/08/2009 11:32:00 AM From: Guzman, Richard Created By: Richard.Guzman@nrc.gov Recipients:

John.Dosa@constellation.com ('Dosa, John J')

Tracking Status: None Dennis.Vandeputte@constellation.com ('Vandeputte, Dennis E')

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 15723 07/08/2009 Options Expiration Date:

Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: